LS-based joint estimation of carrier frequency offset and IQ imbalance in OFDM systems

In this paper, two non-ideal effects, carrier frequency offset (CFO) and IQ imbalance, are jointly compensated for an orthogonal frequency division multiplexing (OFDM) system. Based on the two identical sequences in the preamble, a LS-based method is proposed to estimate both CFO and IQ imbalance. This method has much lower complexity than the state-of-art expectation-maximization (EM) approach. Simulation results show that the proposed algorithm is robust for a wide SNR range, and performs better in the estimation of the IQ imbalance.